Simple bone cysts [
Minimally invasive technique preserves periosteum, muscles, and blood supply. With curettage cyst decompression and the use of allogenic bone graft, the technique has easy and effective approach.
A 14-year-old boy presented with chief complaints of pain and swelling over right upper arm and difficulty to move it for 3 days. Mild pain at the right upper arm had been present for around 2 months for which he did not bother. Pain was suddenly increased three days back while he was trying to lift water bucket. On general physical examination, patient had adequate built and nutritional status for his age with no abnormality in general examination. In local examination, tenderness, bony irregularity, and crepitus were present over right proximal humerus. Range of motion was painfully at the right shoulder. Plain radiographs of right upper arm and shoulder revealed central multiloculated lytic lesion with well-defined margins at proximal metadiaphysis with transverse fracture line running through lytic lesion with no new bone formation or parosteal reaction. Laboratory evaluation including complete blood counts with peripheral smear, ESR, serum electrolyte with calcium and phosphate, serum albumin and globulin, renal function test, hepatic function tests, urinalysis and parathyroid hormone all came out to be within normal limits. As per the criteria defined by Chang et al. [
The patient was planned for percutaneous cyst curettage and filling of the cyst cavity with deep freezed gamma irradiated allogenic cancellous bone graft under image intensifier guidance under general anesthesia (Figure
The patient was taken in supine position under general anaesthesia. A small longitudinal skin incision 1.5 cm is made proximal upper arm in the upper extremity and fenestration was created in outer cortex of proximal humerus with 3.2 mm drill bit percutaneously under the guidance of image intensifier. An infant feeding tube was inserted to aspirate out the contents of the cyst which were sent for tissue analysis, a larger suction catheter was introduced, and copious irrigation of the bone cyst was carried out. Flexible titanium elastic nail of 3 mm passed through curved end to break the septae and curette the cyst wall, serosanguinous material content of cyst aspirated and collected through suction catheter. Tip of the nail was advanced distally in medullary canal to further decompress the cyst. Finally allogenic Morselized cancellous bone graft prepared and mixed with aspirated bone marrow packed into the cyst cavity through the drill sleeve under the guidance of image intensifier till whole of the cyst was visibly filled with bone graft wound was closed with skin suture and stabilized with “U” slab. Biopsy report confirmed the cyst to be simple bone cyst. The patient was followed up at regular interval, at 10-week follow-up plain skiagram and CT scan showed healing of fracture and resolution of lesion and the patient was able to attain full range of motion at both the shoulder and elbow joint (Figure
Cystic bone lesions in the first two decades of life constitute common cause for pathological fractures. Two most important differential diagnoses of cystic lesions in children include unicameral bone cyst and aneurysmal bone cyst.
Proposed pathogenesis [
Open curettage and bone grafting have significant surgical morbidity [
(a) Preoperative skiagram showing lytic lesion with pathological fracture and (b) intraoperative image intensifier skiagram filling of cavity with allogenic bone graft. (c) Follow-up skigam at the 6 month. (d) Follow-up skiagram at most recent follow up at 1 year showed complete healing (more than 95% opacification).
(a) Deep freezed gamma irradiated allogenic bone graft stored in double jar container. (b) Intraoperative picture of graft preparation. (c) Allobone graft before and after mixing with bone marrow. (d) Percutaneous packing of bone graft after curettage and decompression.
Follow-up CT scan showing healing of lesion.
Current surgical technique uses minimally invasive method using the curved end of flexible titanium nail introduced percutaneously for curettage of cyst lining and decompression of cyst (Figure
Diagram showing (a) approach for curettage, (b) percutaneous bone grafting, and (c) titanium flexible nail with curved end.
In the study by Wright et al. [
The outcome of the method determined this minimally invasive procedure (healing, as determined radiographically by chang et al. [
In summary, percutaneous method under image intensifier guidance using flexible nail for curettage cyst decompression along with allogeneic bone graft is one of the treatment options that may be considered although the method and its effect need further trials, larger series, and comparison with other available treatments to establish its effectiveness.